Guide coat?

[johnyrotten]

I've seen some absolutely beautiful paint jobs done by some of the members here, I'm wondering if anyone used a guide coat product while sanding out primer or is that just overkill at this scale. I've used it on my 1:1 projects, and it works great at least for me. 

[W Humble]

When I don't, I often regret it!  Simple as using two colors of primer, but make the second a light once-over.  For a gazillion years, body shops used this method (often with just dusting the surface with cheap silver rat-can paint), but now there is a more sophisticated system using black powder and a puff-like sponge.  3M, I think.  Overkill for a 1/25 kit.  A great step toward a better underlayer, which makes or breaks a paint job!  Wick, once PPG guy.

[johnyrotten]

7 hours ago, W Humble said:

When I don't, I often regret it!  Simple as using two colors of primer, but make the second a light once-over.  For a gazillion years, body shops used this method (often with just dusting the surface with cheap silver rat-can paint), but now there is a more sophisticated system using black powder and a puff-like sponge.  3M, I think.  Overkill for a 1/25 kit.  A great step toward a better underlayer, which makes or breaks a paint job!  Wick, once PPG guy.

Thanks for the reply,  I used it when painting my motorcycle (that's my first "pro-level" paint job. No rattle cans involved) I found it really helped get everything leveled out and straight.  I've read about different shade primers while blocking out, seems at this scale that may be a better option. 

[W Humble]

John,

I believe in guide coating, and I know that the color sanding process is very effective, tho I don't belabor it on my kits.  A great restoration shop shooter once told me:
Hell, some of those sanding grits; you might as well just use the back side of the paper!"  

I'm sensitive to the problem with the 2K process paints; super wetlook shine, but the clear builds so deep it gets all out of scale.  Strike a balance, I guess.  I always used PPG 660 Hi Perf clear, but I know that many good body shops use the better rat-can clears for spot repairs -- must be okay, exposed to UV and IR rays, etc. -- so I've been using UPOL brand aerosol clear, and it seems pretty equal.  With our cars not being 'parked in the weather' it isn't a t much risk, huh?!  Just always and lightly on the hig spots, ribs, etc.  Makes the hobby interesting, anyway.  

Wick, and gettin' old!

[Ace-Garageguy]

For the smaller scales, I personally think it's overkill.

BUT...it kinda depends on how good your vision is, how good your lighting is, whether you use magnification when color-sanding, and how rough or slick you can get your primer.

The full-scale shop I work with that consistently turns out world-class paint, even on collision repairs, uses guide-coat on everything.

[Dave G.]

To me run some tests with your current system. Are there any sand scratches in your final finish ? If not, you're covered. If there are, then guide coat to me is merely an option. But it may be that simply more sanding and finer grits will get you there just as well. Also to me, the grits in modeling are fine enough to render guide coat kind of useless, since beyond about 320 or 400 grit you're ,even in 1/1, guide coat is over with. You're final sanding at that point.

It may be different for custom builders with lots of putty work. I'm not one of those.

[Bainford]

I have found a guide coat to be very helpful when attempting to make a subtle correction in the shape or curve of a kit's body panel. It can show me where I am making progress, and where I am just following the existing curve.

[stitchdup]

i'll use a guide coat if i've done lots of bodywork and use filler primer, and i usually use ground up chalk/charcoal as it shows pinholes better than a paint guide coat but the final go is paint once i'm sure the pinholes are gone. if its normal primer i dont usually bother though

[oldcarfan]

My paint jobs are not that good, but I always use a guide coat. I use primer on all the bodies. It makes such a difference both in the preparation and the finish. It might be a little heavy, but I mostly use standard Duplicolor sandable grey and sometimes do a speckle spray of their Hot Rod Grey which is actually a dark rubber color. Then I take it out into the sun and look for mold lines and issues to start sanding on. Then it's more priming, and sanding until I get  smooth finish, or I get tired of messing with it. Wash, rinse, repeat.